This invention is related to a device for attachment of two units provided for rotation in unison about an axis, said device comprising means for axial and radial attachment of the units relative to each other. The invention is intended to be used universally for attaching units of arbitrary nature. A presently preferred use is, however, that a first of the units is rotatably supported in a carrier forming part of a sawing machine whereas the second of the units comprises or is provided for connection to a sawing tool.
Conventional prior art in connection with such a sawing machine is that the sawing machine comprises a threaded pin on which a saw blade is threadable by a hole provided in the blade. A nut is caused to engage with the threaded pin so as to press the saw blade against a support surface arranged around the threaded pin. A non-threaded portion of the threaded pin itself and the edge of the hole in the saw blade may serve for centering the saw blade or, alternatively, the sawing machine and the sawing blade may be provided with any other type of centering arrangement to ensure that the axis of rotation of the saw blade will coincide with the axis of rotation of the rotatable unit of the sawing machine. Another mode of fixing the saw blade is that the saw blade presents a central hole, in which a projectioin on the rotatable unit of the sawing machine may be received while guiding the saw blade, whereas the saw blade itself is fixed to the rotatable part of the sawing machine by a rim of shrews externally of the projection.
In all embodiments known so far, the structure has been such that it has been necessary, in order to establish the engagement between the sawing blade and the movable unit of the sawing machine, to move the saw blade considerably along the axis of rotation. This requires a considerable space. In connection with such sawing machines, for example, which are intended for sawing in concrete and similar and which are moved along the surface, in which sawing cuts are to be provided, there is a need for placing sawing cuts very close to adjoining walls, floors or ceilings. In such a case a need for replacement of the blade may necessitate dismounting of the entire sawing machine from the guide, which is time consuming and laborious.
The object of the present invention is to devise ways to develop the device for attachment of two units provided for rotation in unison about an axis, the device comprising means for axial and radial attachment of the units relative to each other so as to eliminate or at least reduce the disadvantage discussed hereinabove. Thus, the invention alms at creating improved possibilities to replace one of the two units, the unit to be replaced possibly being formed by the saw blade discussed above, without the replacement necessitating a considerable free space in the axial direction.
This object is fulfilled according to the invention by designing the device such that the attaching means comprise first engagement members engageable with each other and provided on the first and second units, said engagement members being adapted to be caused to engage with each other by a radial relative movement between the units. This creates possibilities to bring the units into mutual engagement with a minimum requirement for space in the axial directions.
It is preferred that the first and second units comprise engaging second engagement members adapted to radially guide the units relative to each other. In this way efficient radial guiding, i.e. centering, of the units relative to each other is ensured despite the fact that the units are brought into engagement with each other by a radial relative movement.